U.S. Pat. No. 4,613,090 discloses a yarn winding apparatus of the described type and which includes a bobbin revolver having two rotatably mounted spindles which are adapted to receive empty bobbins thereon. The bobbin revolver is sequentially rotated so as to bring an empty bobbin mounted on one spindle to a winding position, while moving a full bobbin mounted on the other spindle from the winding position to a doffing position. The yarn is then severed and transferred to the empty bobbin at the winding position. The patent further discloses a plate which can be moved between the empty bobbin and the full bobbin upon the full bobbin being moved to the doffing position, so as to prevent the severed yarn end on the full package from contacting the empty bobbin, or the cross wound package being formed thereon. The disclosed plate however reduces the so called parking time, which is the time available to remove a full package from the winding spindle and to return the plate to its inoperative position. Further, there also exists the risk that the yarn end of the full package may damage the plate, or that the yarn itself may be damaged.
German No. OS 31 46 263 and U.S. Pat. No. 4,339,089 disclose a yarn winding apparatus in which an air jet is directed into the gap between the full package at the doffing position and the empty bobbin at the winding position, which is for the purpose of restraining the outward radial movement of the severed yarn end on the full package. These disclosed devices however, have not proven to be highly reliable.
It is accordingly an object of the present invention to provide an apparatus and method for winding a yarn of the described type, and which overcomes the above noted problems associated with the free yarn end which is formed on the rotating full bobbin when it arrives at the doffing position.
It is a more particular object of the present invention to provide a winding apparatus and method of the described type wherein the parking time for doffing the full packages is not reduced, and wherein damage to the device or to the yarn is avoided.